Comet Hale-Bopp655 light seconds

When Comet Hale-Bopp passed through the inner part of our Solar System in 1997, it was bright enough that it could be seen without a telescope or binoculars for over a year. Many skywatchers may have wondered why there were two tails behind this comet. Comets are often referred to as "dirty snowballs" because they are balls of ice, dust, and rock. When one of these snowballs comes close to the Sun, it begins to heat up and lose dust and gas. The dust that evaporates from the comet follows the comet's orbit while reflecting the Sun's light, thus appearing white. The blue tail shines due to gas from the comet, primarily carbon monoxide, interacting with particles emitted by the Sun, and traces the path of those outflowing solar particles.